Each printhead die in an inkjet pen or print bar includes tiny channels that carry ink to the ejection chambers. Ink is distributed from the ink supply to the die channels through passages in a structure that supports the printhead die(s) on the pen or print bar. It may be desirable to shrink the size of each printhead die, for example to reduce the cost of the die and, accordingly, to reduce the cost of the pen or print bar. The use of smaller dies, however, can require changes to the larger structures that support the dies, including the passages that distribute ink to the dies.